United States Secretary of State Hillary Clinton visited South Africa's former president Nelson Mandela at his office in Houghton, Johannesburg on Friday afternoon, said the Nelson Mandela Foundation.

Clinton and Mandela spent 30 minutes in private conversation before she toured the Nelson Mandela Foundation Center of Memory and Dialogue, the foundation said in a statement.

"I'm delighted, doubly because I had a chance to see Madiba today, but I also got to see the archives and some of the archival material which is being displayed for the first time," Clinton said.

"I saw with my own eyes the very careful record keeping that Madiba did during his life which will be a treasure trove of information, stories, lessons and guidance which generations to come will be able to learn from," Clinton said.

The foundation said it valued Clinton's interest in the work of the Foundation.

(Xinhua News Agency August 8, 2009)